A terrorist attack is like a national Rorschach test. Everybody sees in it what they want — usually something that proves a point they've been making all along.

Even before the Tsarnaev brothers were identified as the perpetrators of the Boston Marathon bombings, speculation about the unknown attackers fell mostly into two camps: They could be Muslim jihadists, or they could be American anti-tax extremists. Guess which suggestion came from liberals and which from conservatives.

Once real suspects were identified, pundits and public officials appropriated the bombings to support their worldviews, citing it to support positions on U.S. counter-terrorism policy, immigration reform and even the endless battle over the budget.

From the right, for example, came a familiar refrain: The attacks in Boston show that the Obama administration isn't serious about fighting terrorism. "How is this a victory for traditional law enforcement?" demanded John Yoo, the UC Berkeley law professor who wrote the legal opinions known as the "torture memos" in the George W. Bush administration. "Law enforcement alone means the nation lies vulnerable to attacks on soft targets and must expend enormous resources to catch the killers afterwards. A preemptive strategy based on intelligence and the use of force overseas seeks to prevent such attacks further from our shores. That option should be preferred by everyone compared to what we've seen in Boston these last five days."

Professor Yoo must not have noticed the thousands of drone strikes President Obama has ordered against suspected terrorists in Pakistan and Yemen. Whatever the deficiencies of Obama's counter-terrorism policy, "law enforcement alone" doesn't come close to describing it.

From the far reaches of the left came an equally disconnected complaint: The Boston bombings, Princeton University's Richard Falk suggested, were a form of "resistance" to what he called "the American global domination project." Never mind that neither Tsarnaev brother had any known views on U.S. foreign policy at all.

In Congress, members took Dzhokhar Tsarnaev's arrest as an opportunity to rehash a debate over whether alleged terrorists should be held as civilians or detained as "enemy combatants" under the laws of war.

Several Republicans, led by Sen. Lindsey Graham of South Carolina, denounced the administration for failing to put Tsarnaev in military detention — even though, under a law Graham supported, that measure is reserved for members of Al Qaeda, the Afghan Taliban or allied organizations, and no evidence indicates Tsarnaev was part of any of those groups.

On the other side of that debate, along with the usual liberal suspects, was another Republican, the libertarian Sen. Rand Paul of Kentucky. "I think we can still preserve the Bill of Rights," he said. "I see no reason why our Constitution is not strong enough to convict this young man with a jury trial."

But Paul had another point he wanted to make: The bombings, he said, bolstered his view that Congress should move slowly on immigration reform. "We should not proceed until we understand the specific failures of our immigration system," he argued (right before he misidentified where the brothers came from). "Why did the current system allow two individuals to immigrate to the United States from the Chechen Republic in Russia, an area known as a hotbed of Islamic extremism, who then committed acts of terrorism?"

But to those who want to move fast on an immigration bill, the bombings were another reason to speed up. "Immigration reform will make us safer," said Sen. Richard J. Durbin (D-Ill.), arguing that bringing illegal immigrants out of the shadows might encourage them to cooperate with law enforcement.

Both points seemed only tangentially connected to the circumstances of the Boston case. But that didn't stop the point-scoring for a moment.

For Graham and others, Boston was all about an "intelligence failure," although it wasn't clear exactly where the failure was. For New York Mayor Michael R. Bloomberg, the lesson was that mayors and police chiefs need more powers on the ground. "Our laws and our interpretation of the Constitution, I think, have to change," he said. And for House Democratic Whip Steny H. Hoyer (D-Md.), it was a lesson in the dangers of the current federal budget sequester — one of many reasons, he said, to avoid "cutting the highest priorities and the lowest priorities by essentially the same percentage."

What did all these debating points have in common? Insufficient information.

Were the Tsarnaevs acting at the behest of foreign terrorists? Did they deceive the U.S. immigration system? Could their intentions have been detected ahead of time by a more vigilant FBI? And did we lose anything by reading Dzhokhar Tsarnaev his Miranda rights on Monday?

We don't know yet. We could always wait to find out. But for anyone with a cause to push, a talking point is a terrible thing to waste.